The combination of pthread_rwlock_t and signals causes spurious
deadlocks on Mac (see linked issue).
This adds a cctest which tests this combination. This test is skipped on
Mac, where it would deadlock. This test can be used to document and
further investigate the issue, and test potential fixes.

R=jkummerow@chromium.org

Bug: v8:11399
Change-Id: I5d1fcdd84db253ec2d0637575239f212aae2ecb7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2856553Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74662}